A sequence-independent method to turn genomic DNA into libraries of hairpins. An efficient way to get a different adapter on each end of a DNA fragment is to clone it and digest the fragment back out. Design the vector to have unique restriction sites outside the unique regions you want to put on each end. After digestion, your DNA fragments will have two different "adapters" on each end.Adapted from: Wang L., Zheng J., Luo Y., Xu T., Zhang Q., Zhang L., Xu M., Wan J., Wang MB., Zhang C., Fan Y. 2013. Construction of a genomewide RNAi mutant library in rice. Plant Biotechnology Journal 11:997–1005. DOI: 10.1111/pbi.12093.